I am not getting your point. You should start to learn PHP tutorials. You can use MYSQL data from one page to another page using the SESSION variable. In PHP, the session variable stores the value. We can access that MYSQL database data values in another page. It helps to secure and access website data. A session is a small file that can store data and access data.
You should learn the session and session variable for example.
References -
Session in PHP
Login with session using PHP and MYSQL database